NOVEL FUNCTIONS FOR NUCLEAR FACTORS IN THE CYTOPLASM - THE SEX-LETHALPARADIGM

In recent years, novel functions for a number of nuclear factors have been uncovered in the cytoplasm, mainly at the level of translation. T hese factors behave as multifunctional regulators of gene expression a nd many play key roles in cell differentiation and development. One of the best characterized examples is that of Sex-lethal (SXL) an RNA-bi nding protein that is expressed in female Drosophila flies and control s sex determination and dosage compensation. Recent findings indicate that SXL, a paradigmatic regulator of splicing also controls translati on of target mRNAs. This review attempts to summarize this evidence an d provide an overview of 'nuclear factors' with roles in translation. (C) 1997 Academic Press Ltd.